Project Summary Over the last 3 decades, use of prescription drugs has increased by more than 60%, and prevalence of prescription drug use among pregnant women is currently estimated around 50%. Children born to women who abuse prescription medications are more likely to be born with neonatal abstinence syndrome, the incidence of which has doubled in the past 5 years. Recent national survey data show that the rate of current illicit drug use is 14.6% among pregnant adolescents, 8.6% among young adults, and 3.2% among adults. The first step in identifying both prescription drug abuse and illicit drug use during pregnancy is screening; however, no specific substance use screener has been recommended for use with pregnant women to identify illicit or prescription drug use. The proposed study will compare and validate three existing substance use screeners - 4 P?s Plus, NIDA Quick Screen/ASSIST, and the Substance Use Risk Profile-Pregnancy scale - among at least 500 pregnant women stratified by trimester of pregnancy presenting to two primary care clinics in Baltimore over 1 year. Specific aims are to: (1) conduct validity analyses to determine sensitivity, specificity, usability, and how each scale compares to the others and to the gold standard of urine and hair drug testing in identifying prescription and illicit drug use; (2) determine the impact of clinic population variables (age, race, trimester of pregnancy) on validity of the three substance use screeners; and (3) assess birth outcomes (birth weight, gestational age, head circumference, and NICU admissions) associated with the most widely used prescription drug and multi-drug exposure. The end goal of the study is to determine which screening tool(s) is most effective in identifying prescription drug abuse and illicit drug use among pregnant women so that evidence- based guidance may be offered to clinicians, utilizing biochemical drug testing as the gold standard to designate use and electronic medical records (EMR) as a supplement to identify prescribed drugs. Aim 3 was added to capture the important and relevant associations between the drug use and birth outcomes.